ARTHUR’S PASS QUAKE.

Hauraki Plains Gazette, Volume XXXX, Issue 5405, 27 March 1929, Page 2

ARTHUR’S PASS QUAKE.

THEORY Ob THE CAUSE.

Commenting, cm the recent earthquake in the South island, a Christchurch paper says :■—

“We are in the habit of- saying that cannot be accounted for, and come upon us without notice or warning of. any kind. It is true that we cannot predict the precise mom nt or the exact place where the next earthquake will occur, but the general and the districts in which they may be. expected, are quite well km-wm Most people associate earthquakes with volcanoes. Frequent tietnors of the earth and sudden uphep vajs of the surface do, of course, occur in- connection with volcanic eruptions, but the most destructive earthquakes are due to other and mere silent and unnoticed causes,. The must of the eaith is always in a state of .strain, due to the pressure, of the more superficial parts o,n t.he supporting structures below, and while a ceniJilion cf equilibrium is maintained under ordinary changes are .continually taking place, and the e;arth below must adjust itself to the; altered weights; and stresses. If the adjustment is made gradually all may be well, but along places where the crust is weak there may be a sudden giving way, with earthquakes as a result. For countless ages, denudation has bqen. going on at a very rapid rate along the line of the Southern Alps, and enormous quantities of material have been remdved, to be carried down by the great rivers of. the Canterbury Plains l and deposited on the plans themselves or out at sea. The downward pressure at places like Arthur’s Ppss has been lessened, while the weight to be supported further east has increase-d, and the recent earthquake, felt mast severely at Arthur’s Pass, appears to be a sign that there has been a sudden adjustment slightly to the east of the main rangc> If this movement has fully relieved the strain there may follow a iqngjffiy period of quiet, but it would be rash to anticipate, for, on the other hand, now that some structures have given way other weak places may be exposed to the strain and have to give wayin thegr turn. Further immediate results cannot be foreseen, but the important fact to be noted is that the possibility of subsequent earthquakes should be taken into account by those who are responsible for buildings at Arthur’s Pass or in other places, such as Christchurch, where/ people are living close together.